NEW YORK: The National Football League intentionally omitted at least 100 cases of concussion in research aimed at downplaying the risk of head injuries in the sport, the New York Times reported on Friday.

The Times report said the NFL used data from between 1996 and 2001, claiming it was comprehensive despite knowing it did not include key information from multiple teams.

The report cited the example of the Dallas Cowboys. Zero concussions were reported by the team during the period despite the fact that legendary quarterback Troy Aikman had suffered several well-documented head injuries before his retirement in 2000.

In total, the NFL research omitted around 10 percent of the documented concussions, the Times reported. The study was published in 2003 when it was presented as a full account of diagnosed concussions reported by team doctors over the five-year period.

“It should be an unmistakable red flag that a team does not report any concussions over multiple years,” Robert Cantu, one of the peer-reviewers of the study, told the Times.

The NFL issued a strongly worded rebuttal of the Times report, denying that any omitted data was the result of a deliberate desire to play down health risks.

It said the Times report had “intentionally ignored the facts.”

“The studies that are the focus of the Times’ story used data collected between 1996-2001,” the statement read. “They were necessarily preliminary and acknowledged that much more research was needed. Since that time, the NFL has been on the forefront of promoting and funding independent research on these complex issues. Further, the data from the Mild Traumatic Brain Injury (MTBI) Committee studies have not been used in any way by the current Head, Neck and Spine Committee in its research on player health and safety.

“Contact sports will never be concussion-free, but we are dedicated to caring for our players, not just throughout long careers but over the course of long lives,” the league added.

However a member of the NFL’s concussion committee, Joseph Waeckerle, said he was unaware data was missing.

“If somebody made a human error or somebody assumed the data was absolutely correct and didn’t question it, well, we screwed up,” Waeckerle told the Times. “If we found it wasn’t accurate and still used it, that’s not a screw-up; that’s a lie.”

The Times report comes amid increasing concerns about the long-term health risks faced by American football players.

Last week the NFL’s top health executive became the first senior official from the league to acknowledge a link between football-related head trauma and the brain disease chronic traumatic encephalopathy.

In recent years, nore than 100 deceased players have been found to be suffering from CTE, which can result in memory loss, dementia and depression.

In April last year, the NFL agreed to settle a lawsuit and pay $765 million to about 5,000 former players over health claims.

A Hollywood movie starring Will Smith as the neuropathologist who helped make the link between concussions sustained by NFL players and CTE hit theaters last year.